1. Field of the Invention
Embodiments of the present invention relate generally to a mobile terminal and controlling method for the mobile terminal. More specifically, embodiments of the present invention relate to a mobile terminal and control method for the mobile terminal for maintaining an A/V session when a handover occurs between heterogeneous networks.
2. Description of the Related Art
The number of wireless Internet users is increasing with the rapid prevalence of the Internet, the development of wireless communication technology, and the improved performance of mobile terminals such as a portable computers and personal digital assistants (PDAs). The Internet environment further enables mobile terminals to occasionally move around and change their network access points.
To support the Internet communication of the mobile terminal, high quality Internet service should be ensured for a subsequent network environment as well as the current network environment, even when the mobile terminal moves from the current network area to the subsequent network area. That is, the mobile terminal needs to seamlessly communicate during the move, for which handovers have been introduced. Handovers can be divided into horizontal handovers and vertical handovers (VHO). The VHO is a handover performed between heterogeneous networks.
The development of the Internet has further led to the generalization of real-time multimedia services including video on demand (VOD), audio on demand (AOD), picture phone and video chatting. Especially, considering that the development of the wireless Internet and the enhanced data processing of terminals has enabled real-time multimedia services for mobile terminals and has accelerated the market extension relating to such services. Accordingly, users may be provided with various real-time multimedia services through mobile terminals while moving from place to place.
In the related art, when mobile terminals change their locations while maintaining multimedia services, a Session Initiation Protocol (SIP) capable of supporting mobile Internet protocol (IP) or mobility is required to maintain continuity of an A/V session. The mobile IP is for a mobile terminal using an IP. When the mobile terminal accesses a remote network from outside of a home network, and registers an address acquired at a current network in a home agent, the home network forwards data to the mobile terminal connected to the remote network. The use of the mobile IP requires the installation of the home agent and loading of a mobile IP protocol stack. Thus, manufacturing costs of the mobile terminals increase, with the current solutions requiring a long time to process the mobile IP.